2 ; Driver for the Inkwell Systems 170-C and 184-C lightpens.
4 ; 2013-07-01, Greg King
7 .include "zeropage.inc"
8 .include "mouse-kernel.inc"
13 ; ------------------------------------------------------------------------
14 ; Header. Includes jump table.
22 .byte $6d, $6f, $75 ; ASCII "mou"
23 .byte MOUSE_API_VERSION ; Mouse driver API version number
46 .byte MOUSE_FLAG_EARLY_IRQ
48 ; Callback table, set by the kernel before INSTALL is called.
50 CHIDE: jmp $0000 ; Hide the cursor
51 CSHOW: jmp $0000 ; Show the cursor
52 CDRAW: jmp $0000 ; Draw the cursor
53 CMOVE: jmp $0000 ; Prepare to move the cursor
54 CMOVEX: jmp $0000 ; Move the cursor to X co-ord.
55 CMOVEY: jmp $0000 ; Move the cursor to Y co-ord.
58 ;----------------------------------------------------------------------------
61 ; This driver is for the 40-column screen.
66 SCREEN_WIDTH = XSIZE * 8
67 SCREEN_HEIGHT = YSIZE * 8
70 ;----------------------------------------------------------------------------
71 ; Global variables. The bounding box values are sorted so that they can be
72 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
77 ; Default values for below variables
78 ; (We use ".proc" because we want to define both a label and a scope.)
83 .word SCREEN_WIDTH - 1 ; XMax
84 .word SCREEN_HEIGHT - 1 ; YMax
85 .byte %00000000 ; Buttons
91 XMin: .res 2 ; X1 value of bounding box
92 YMin: .res 2 ; Y1 value of bounding box
93 XMax: .res 2 ; X2 value of bounding box
94 YMax: .res 2 ; Y2 value of bounding box
95 Buttons: .res 1 ; Button status bits
97 XPos: .res 2 ; Current lightpen position, X
98 YPos: .res 2 ; Current lightpen position, Y
100 OldPenX: .res 1 ; Previous HW-counter values
107 ; Default Inkwell calibration.
108 ; The first number is the width of the left border;
109 ; the second number is the actual calibration value.
111 XOffset: .byte (24 + 24) / 2 ; x-offset
113 ; Jump to a function that puts a new calibration value into XOffset.
119 ;----------------------------------------------------------------------------
120 ; INSTALL routine. Is called after the driver is loaded into memory. If
121 ; possible, check if the hardware is present.
122 ; Must return a MOUSE_ERR_xx code in .XA.
126 ; Disable the BASIC interpreter's interrupt-driven sprite-motion code.
127 ; That allows direct access to the VIC-IIe's sprite registers.
134 ; Initiate variables. Just copy the default stuff over.
136 ldx #.sizeof (DefVars) - 1
147 ; Call a calibration function through the library-reference.
151 sta ptr1 ; Point to mouse_adjuster
155 bze @L1 ; Don't call pointer if it's NULL
156 sta Calibrate+2 ; Point to function
160 lda #<XOffset ; Function will set this variable
164 ; Be sure that the lightpen cursor is invisible and at the default location.
165 ; It needs to be done here because the lightpen interrupt handler doesn't
166 ; set the lightpen position if it hasn't changed.
171 lda #<(SCREEN_HEIGHT / 2)
172 ldx #>(SCREEN_HEIGHT / 2)
174 lda #<(SCREEN_WIDTH / 2)
175 ldx #>(SCREEN_WIDTH / 2)
185 ;----------------------------------------------------------------------------
186 ; UNINSTALL routine. Is called before the driver is removed from memory.
187 ; No return code required (the driver is removed from memory on return).
190 jsr HIDE ; Hide cursor on exit
195 ;----------------------------------------------------------------------------
196 ; HIDE routine. Is called to hide the lightpen pointer. The mouse kernel manages
197 ; a counter for calls to show/hide, and the driver entry point is called only
198 ; if the mouse is currently visible, and should get hidden. For most drivers,
199 ; no special action is required besides hiding the lightpen cursor.
200 ; No return code required.
207 ;----------------------------------------------------------------------------
208 ; SHOW routine. Is called to show the lightpen pointer. The mouse kernel manages
209 ; a counter for calls to show/hide, and the driver entry point is called only
210 ; if the mouse is currently hidden, and should become visible. For most drivers,
211 ; no special action is required besides enabling the lightpen cursor.
212 ; No return code required.
219 ;----------------------------------------------------------------------------
220 ; SETBOX: Set the lightpen bounding box. The parameters are passed as they come
221 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
222 ; No checks are done if the lightpen is currently inside the box, that is the job
223 ; of the caller. It is not necessary to validate the parameters; trust the
224 ; caller; and, save some code here. No return code required.
227 stx ptr1+1 ; Save data pointer
229 ldy #.sizeof (MOUSE_BOX) - 1
240 ;----------------------------------------------------------------------------
241 ; GETBOX: Return the lightpen bounding box. The parameters are passed as they
242 ; come from the C program, that is, a pointer to a mouse_box struct in .XA.
245 stx ptr1+1 ; Save data pointer
247 ldy #.sizeof (MOUSE_BOX) - 1
254 ;----------------------------------------------------------------------------
255 ; MOVE: Move the mouse to a new position. The position is passed as it comes
256 ; from the C program, that is: X on the stack and Y in .XA. The C wrapper will
257 ; remove the parameter from the stack on return.
258 ; No checks are done if the new position is valid (within the bounding box or
259 ; the screen). No return code required.
262 MOVE: sei ; No interrupts
270 jsr MoveX ; Move the cursor
272 cli ; Allow interrupts
275 ;----------------------------------------------------------------------------
276 ; BUTTONS: Return the button mask in .XA.
282 ; Make the lightpen buttons look like a 1351 mouse.
285 asl SID_ADConv2 ; PotY
288 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
291 ;----------------------------------------------------------------------------
292 ; POS: Return the lightpen position in the MOUSE_POS struct pointed to by ptr1.
293 ; No return code required.
295 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
297 sei ; Disable interrupts
298 lda XPos ; Transfer the position
307 cli ; Enable interrupts
310 sta (ptr1),y ; Store last byte
313 ;----------------------------------------------------------------------------
314 ; INFO: Returns lightpen position and current button mask in the MOUSE_INFO
315 ; struct pointed to by ptr1. No return code required.
317 ; We're cheating here, to keep the code smaller: The first fields of the
318 ; mouse_info struct are identical to the mouse_pos struct; so, we'll just
319 ; call _mouse_pos to initiate the struct pointer, and fill the position
324 ; Fill in the button state
326 jsr BUTTONS ; Will not touch ptr1
327 ldy #MOUSE_INFO::BUTTONS
331 ;----------------------------------------------------------------------------
332 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
333 ; specific data in ptr1, and the ioctl code in .A.
334 ; Must return an error code in .XA.
337 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
338 ldx #>MOUSE_ERR_INV_IOCTL
341 ;----------------------------------------------------------------------------
342 ; IRQ: IRQ handler entry point. Called as a subroutine, but in the IRQ context
343 ; (so, be careful). The routine MUST return carry set if the interrupt has been
344 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
345 ; MUST return carry clear.
350 ; Record the state of the buttons.
351 ; Try to avoid crosstalk between the keyboard and the lightpen.
353 ldy #%00000000 ; Set ports A and B to input
355 sty CIA1_DDRA ; Keyboard won't look like buttons
356 lda CIA1_PRB ; Read Control-Port 1
357 dec CIA1_DDRA ; Set port A back to output
358 eor #%11111111 ; Bit goes up when button goes down
361 lda #%11101111 ; (Don't change bit that feeds VIC-II)
362 sta CIA1_DDRB ; Buttons won't look like keyboard
363 sty CIA1_PRB ; Set "all keys pushed"
365 ; Read the VIC-II lightpen registers.
370 ; Skip processing if nothing has changed.
375 ; Subtract the height of the top border, so that the lightpen co-ordinate
376 ; will match the TGI co-ordinate.
379 tay ; Remember low byte
382 ; Limit the Y co-ordinate to the bounding box.
402 @SkipY: lda VIC_LPEN_X
405 ; Skip processing if nothing has changed.
410 ; Adjust the value by the calibration offset.
414 ; Calculate the new X co-ordinate.
415 ; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits.
416 ; Therefore, the VIC-II number is doubled. Then, it points to every other pixel;
417 ; but, it can reach across the screen.
420 tay ; Remember low byte
423 tax ; Remember high byte
425 ; Limit the X co-ordinate to the bounding box.
447 clc ; Interrupt not "handled"
450 ; Move the lightpen pointer to the new Y pos.
456 ; Move the lightpen pointer to the new X pos.